Thoughts from the intersection of science, pseudoscience, and conflict.

genomics

I’ve been waiting for this paper for months! The Willerslev group has just published the results of their study on ancient DNA from Paleo-Eskimos in the North American Arctic. Unfortunately, this article is behind a paywall at the journal Science, but I’ll give you a brief summary of the results, and talk a bit about why this paper matters and what it means for our understanding of the peopling of the Americas. Continue reading →

In recent weeks, Nicholas Wade’s book A Troublesome Inheritance has been soundly criticized on the basis of his misunderstanding (or misrepresentation) of the statistical methods used to study human genetic variation (see Jeremy Yoder’s critique here, Chris Smith’s here, Joseph Graves’ here, and mine here ), his misunderstanding of evolution (see Michael Eisen’s critique here, and Eric Michael Johnson’s here ), and his misunderstanding of human biological variation (see Greg Laden’s critique here, Agustin Fuentes’ critique here, and Jon Marks’ here ). These criticisms–all from biologists and biological anthropologists– can be boiled down into a single statement: Mr. Wade’s book is scientifically unsound.

His responses thus far (to those of us who published in the Huffington Post) have failed to engage any of the substantive issues that have been raised. Instead, he dismissed our standing for discussing this issue, calling me a “postdoctoral student” (A science journalist should be aware that postdocs aren’t students), and dismissing Dr. Fuentes’ and Dr. Marks’ research background and credentials (as if biological anthropologists were not scientists). I have not seen any response yet to the numerous other critiques from biologists that have appeared elsewhere (many listed in the previous paragraph), which raise many of the same concerns.

Mr. Wade may feel that he can ignore the substantive critiques of his book by scientists. But can he do the same for fellow science journalists? David Dobbs’ review of Mr. Wade’s book appeared in the New York Times Book Review this past Sunday (the online version can be read here). It is not favorable. Mr. Dobbs calls the book “deeply flawed, deceptive, and dangerous.”

In discussing the study (critiqued by most of us above) that Mr. Wade claims supports the genetic basis for three (or is it five?) “continental races”, Mr. Dobbs notes that the paper itself

“directly contradicts Wade’s argument. Yet he baldly claims the study as support. And he does this sort of thing repeatedly: He constantly gathers up long shots, speculations and spurious claims, then declares they add up to substantiate his case. The result is a deeply flawed, deceptive and dangerous book.”

“Wade demonstrates how a lucid, well-written, selective presentation of evidence — eloquent, elegant cherry-picking — can convince smart people of pernicious ideas that seem scientific, but which science does not support. Much of the sleight of hand in this book will not be evident to people who don’t know the field. In some cases one has to read a specific paper cited by Wade to recognize that he thoroughly misrepresents its findings.”

I encourage you to go read both of Mr. Dobbs’ critiques. It will be interesting to see how Mr. Wade responds.

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Update: Here are a few other critiques worth mentioning:

“…for he has no right to give names to objects which he cannot define.” –Charles Darwin

Do “races” exist as meaningful biological categories? Physical anthropologists and human biologists have been studying race (i.e., blacks vs. whites, or Europeans vs. Asians) for centuries. For most of that time, they subscribed to the perspective that race was a taxonomic category, and they sought to identify the biological characteristics (such as cranial shape or skin color) that characterized and defined these different groups. This perspective assumed that each individual was a member of a single racial category, that the differences between racial categories were biological, and that these categories were predictive of other traits (such as ancestry, temperament, intelligence, or health).

But it gradually became clear that this understanding was not scientifically sound. Groupings of people by skin color did not produce the same result as groupings of people by skull shape, nor of blood type. Furthermore, as scientists began to study human variation with the tools of genetics (in the process creating my fields, anthropological genetics and human population genetics), it became apparent that human genetic variation does not divide humans into a few discrete groups. There are virtually no sharp boundaries, either with physical features or with patterns of genetic diversity, that show where one population “ends” and the next “begins”. Continue reading →

This is the second post in a series discussing the recent publication of a 12,500 year old genome from Montana. You can find the first post here.

In the weeks following the publication of the complete genome from a Clovis child, there’s been a lot of press coverage of this study and its possible implications. I want to discuss a bit of the media coverage on this subject, since it raises issues that I think science journalists need to consider more carefully.

First of all, to recap the major findings of the original study (discussed in more detail at the link above):
1. Anzick-1, the 12,500 year old Clovis child whose genome Rasmussen and colleagues sequenced, is very closely related to living and ancient Native Americans.
2. Anzick-1 is more closely related to Siberians than other Eurasian groups.
3. Anzick-1 is more closely related to Central and South American Native American groups than to some North American groups.
4. The results from Anzick-1’s genome fit with the scientific consensus about the peopling of the Americas. This consensus encompasses the results of decades of archaeological, genetic, and paleoclimate research.

Unfortunately, several press reports chose to find controversy in a decidedly non-controversial story by giving undue weight to problematic “alternative” explanations of Native American origins, including the Solutrean hypothesis, and other “European contributions” to Native American ancestry.

Last Wednesday, Dr. Morton Rasmussen of the Natural History Museum of Denmark and his colleagues announced that they had completely sequenced the genome of an infant boy, buried ~12,600 years ago in Montana. A few weeks earlier, I’d been approached by an editor at Nature, who asked me if I and my mentor Deborah Bolnick would be interested in writing a companion paper that would analyze and contextualize their results. We agreed, and the paper was published in last week’s issue, alongside Rasmussen et al.’s work. Because it’s (unfortunately) behind a paywall, I’d like to summarize what we said in that paper for non-scientists. There are a lot of things to talk about with regard to this study, including a consideration of ethical issues and the media’s response, so I’m likely going to do several posts on it. This first post is mainly a discussion of how we interpret the results.